This study of a monkey model of sarcopenia is in the very early stages. Thus far, muscle biopsies have been collected on only one-third of the squirrel monkeys. The samples are frozen for processing. Biochemical and histological analysis of the muscle sample will be done and include mysoin ATPase activity for determination of muscle fiber type, proportions, and cross-sectional area. Once the biochemical and histological characterization of the aging muscle is complete, the intervention protocol will be determined to target those pathways identified during characterization as most susceptible to aging changes.